Is the husband of the paternal aunt considered among the kindred such that maintaining ties with him is an act of upholding kinship and severing ties with him is an act of cutting it off, taking into consideration that he curses the dead and there are problems between us and him?

Your paternal aunt (ammah) is a kin (raheem), but her husband is not. However, it is not permissible to abandon him unless there is a valid reason. It is advisable to consider what is best in dealing with him and to advise him to stop reviling the deceased, provided they were not disbelievers or immoral individuals, based on the Prophet's (peace be upon him) saying: "Do not revile the dead, for they have gone on to what they have sent forth."

Scholars have unanimously agreed on the permissibility of reviling deceased disbelievers and immoral individuals as a warning against them. It is recommended to strive for reconciliation between you, based on Allah’s (the Most High) saying: "So fear Allah and amend that which is between you," and His saying: "The believers are but brothers, so make reconciliation between your two brothers." The Prophet (peace be upon him) said: "Reconciliation between people is better than the degree of fasting, prayer, and charity, and discord between people is the shaver." We advise you to forgive and concede, based on His (the Most High) saying: "But whoever pardons and makes reconciliation - his reward is due from Allah."